Micro Vacuum Pump DC 3V 6V 60KPA High Negative Pressure Low Flow Air Pump Water pump For Cupping Device Fish Tank 0.5L/min (White, 3V 2PCS)

There is a little blurb in the technial section that says this pump has a life expectancy of over 100 hours. I purchaced the 6 volt one as a trial. I stripped and soldered on a usb cable then hooked it up to a cell phone charger(5 volt). It worked as advertized. Both of mine lasted about 190 hours pumping a salt water solution (fish tank water). In both of them the diaphram for the pump sprung a leak. First was below the water line and leaked water into the motor and seized it up. The second was mounted above the water line, and at the 190 hour mark was still pumping water but sucking a fair bit of air into the pump, from the failed diaphram.

Can't even return it because I never received it. But its also the only pump that will fit the enclosure I have so I've ordered again hoping it actually gets shipped this time.

I ordered a 2 pack. Both of them broke when I applied power. The motor shaft begins to spin freely within the coupler. So the motor is spinning but pump is not working.